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<title>mesg</title>
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The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

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<h4><a name = "tag_001_014_1403">&nbsp;</a>NAME</h4><blockquote>
mesg - permit or deny messages
</blockquote><h4><a name = "tag_001_014_1404">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

mesg <b>[</b>y|n<b>]</b>
</code>
</pre>
</blockquote><h4><a name = "tag_001_014_1405">&nbsp;</a>DESCRIPTION</h4><blockquote>
The
<i>mesg</i>
utility will control whether other users are allowed
to send messages via
<i><a href="write.html">write</a></i>,
<i><a href="talk.html">talk</a></i>
or other utilities to a terminal device.
The terminal device affected
is determined by searching for the first terminal in
the sequence of devices associated with
standard input, standard output and
standard error, respectively.
With no arguments,
<i>mesg</i>
reports the current state without changing it.
Processes with appropriate privileges may be able to
send messages to the terminal independent of the current state.
</blockquote><h4><a name = "tag_001_014_1406">&nbsp;</a>OPTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_1407">&nbsp;</a>OPERANDS</h4><blockquote>
The following operands are supported
in the POSIX locale:
<dl compact>

<dt><b>y</b><dd>Grant permission to other users
to send messages to the terminal device.

<dt><b>n</b><dd>Deny permission to other users
to send messages to the terminal device.

</dl>
</blockquote><h4><a name = "tag_001_014_1408">&nbsp;</a>STDIN</h4><blockquote>
Not used.
</blockquote><h4><a name = "tag_001_014_1409">&nbsp;</a>INPUT FILES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_1410">&nbsp;</a>ENVIRONMENT VARIABLES</h4><blockquote>
The following environment variables affect the execution of
<i>mesg</i>:
<dl compact>

<dt><i>LANG</i><dd>Provide a default value for the internationalisation variables
that are unset or null.
If
<i>LANG</i>
is unset or null, the corresponding value from the
implementation-dependent default locale will be used.
If any of the internationalisation variables contains an invalid setting, the
utility will behave as if none of the variables had been defined.

<dt><i>LC_ALL</i><dd>
If set to a non-empty string value,
override the values of all the other internationalisation variables.

<dt><i>LC_CTYPE</i><dd>
Determine the
locale for the interpretation of sequences of bytes of text data as
characters (for example, single- as opposed to multi-byte characters
in arguments).

<dt><i>LC_MESSAGES</i><dd>
Determine the locale that should be used to affect
the format and contents of diagnostic
messages written (by
<i>mesg</i>)
to standard error.

<dt><i>NLSPATH</i><dd>
Determine the location of message catalogues
for the processing of
<i>LC_MESSAGES .
</i>
</dl>
</blockquote><h4><a name = "tag_001_014_1411">&nbsp;</a>ASYNCHRONOUS EVENTS</h4><blockquote>
Default.
</blockquote><h4><a name = "tag_001_014_1412">&nbsp;</a>STDOUT</h4><blockquote>
If no operand is specified,
<i>mesg</i>
displays the current terminal state in an unspecified format.
</blockquote><h4><a name = "tag_001_014_1413">&nbsp;</a>STDERR</h4><blockquote>
Used only for diagnostic messages.
</blockquote><h4><a name = "tag_001_014_1414">&nbsp;</a>OUTPUT FILES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_1415">&nbsp;</a>EXTENDED DESCRIPTION</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_1416">&nbsp;</a>EXIT STATUS</h4><blockquote>
The following exit values are returned:
<dl compact>

<dt>0<dd>Receiving messages is allowed.

<dt>1<dd>Receiving messages is not allowed.

<dt>&gt;1<dd>An error occurred.

</dl>
</blockquote><h4><a name = "tag_001_014_1417">&nbsp;</a>CONSEQUENCES OF ERRORS</h4><blockquote>
Default.
</blockquote><h4><a name = "tag_001_014_1418">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
The mechanism by which the message status of the terminal
is changed is unspecified.
Therefore, unspecified actions may cause the status
of the terminal to change after
<i>mesg</i>
has successfully completed.
These actions may include, but are not limited to:
another invocation of the
<i>mesg</i>
utility;
login procedures;
invocation of the
<i><a href="stty.html">stty</a></i>
utility;
invocation of the
<i><a href="chmod.html">chmod</a></i>
utility or
<i><a href="../xsh/chmod.html">chmod()</a></i>
function;
and so on.
</blockquote><h4><a name = "tag_001_014_1419">&nbsp;</a>EXAMPLES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_1420">&nbsp;</a>FUTURE DIRECTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_1421">&nbsp;</a>SEE ALSO</h4><blockquote>
<i><a href="talk.html">talk</a></i>,
<i><a href="write.html">write</a></i>.
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Copyright &copy; 1997 The Open Group
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